Conventionally, an image forming apparatus such as an electrophotographic copying machine uses a developer of fine particles. In such an image forming apparatus, the developer is supplied from the developer supply container in response to consumption thereof resulting from image forming operation.
An example of such a developer supply container is disclosed in Japanese Laid-open Patent Application 2010-256893, which employs a drive converting mechanism for converting a rotational force inputted from the image forming apparatus to the developer supply container into a force for operating a displacement type pump portion. In the apparatus disclosed in Japanese Laid-open Patent Application 2010-256893, the pump portion is operated together with a feeding portion of the developer supply container to feed the developer accommodated in the developer supply container, and the developer can be discharged from the developer supply container by the volume change of the pump portion.